Flowers lie near the scene of where Delaware police officers fatally shot an armed man on Wednesday in wheelchair after responding to a call that he had a self-inflicted gunshot wound. Authorities say a shooting occurred and the man died at the scene.

The fatal shooting of a man in a wheelchair by police in Delaware is being investigated by a new attorney general’s department set up to help build public trust.

But the National Association for the Advancement of Colored People (NAACP) has cast doubt over whether the agency can be trusted to carry out a fair investigation, according to the Associated Press.

The group is demanding an independent investigation by a special prosecutor to look into the death of Jeremy McDole, the 28-year-old who was shot in Wilmington after police responded to a call about a man with a self-inflicted gunshot wound on Wednesday. Authorities say they had been told he was still armed.

As with all other police shootings that have resulted in casualties in the state, this week’s incident is being investigated by the Delaware Department of Justice's Office of Civil Rights and Public Trust, which will determine whether any officers will be charged. The police department's criminal investigation and professional standards units are also assisting.

The public trust unit was formed by attorney general and former Lt. Gov. Matt Denn in January. “Among the new unit's responsibilities is conducting investigations where the Department of Justice's other responsibilities might present the appearance of a conflict, such as investigations of use of force by law enforcement officers,” reports the AP.

But Richard Smith, head of the NAACP’s Delaware chapter, said there tends to be a pattern when it comes to police shooting investigations.

Mr. Smith, who met with Lt. Gov. Denn on Thursday, praised the attorney general for doing a good job. But there needs to be a change, he insisted.

“There's been so many shootings, and every time it comes out it was a justified shooting. We cannot continue having all our folks being shot and nobody held accountable," said Smith. “Every time there was a shooting, it came back [a] justified shooting. Everything can't be justified.”

This isn’t the first time special departments created to instill public trust have been called into question.

In Baltimore, a similar unit established by former Baltimore police commissioner Anthony Batts last year was recently overhauled to swap “one Department of Justice review model for another,” according to The Baltimore Sun.

The US Justice Department has stepped in, saying it will conduct its own investigation of police misconduct.

Last year, San Diego Police Chief Shelley Zimmerman also said that the department’s professional standards unit, which once ran inquiries into officer behavior until it was merged with internal affairs, would be brought back, reports The San Diego Union-Tribune.

But Chief Zimmerman, who fielded questions from more than a hundred residents at a 2014 town hall meeting, declined to elaborate on what the unit would do specifically.

"I want it to be very mysterious,” she said. “They are going to proactively go out and find those few officers who make the terrible decision to dishonor the badge. We're going to find them. That's what their role is going to be."